If you are re-using the IDentifiers from your existing tour for your new tour, you can publish the content of your new tour without connecting the object and Start IDentifiers.
As soon as the existing tour has finished you can disconnect the IDentifiers from the old tour and connect them to the new tour and publish again. After that you can archive the old tour. As the content of the new tour is already published and synchronized the synchronization of these added IDentifiers will not take long.
Please pay attention: if your audio has a lot of content of multiple languages we advise to upload, publish and sync one language at a time!